Cement basket



Jan. l., 1946. 1 E- HALL 2,392,145

CEMENT BAS KET Filed May 29, 1943 INVENTOR. 655e E. Ha

Patented Jan. l, 1946 UNITED 'STATES PATENT carica y omar-:Nr msm .im s.neu, weather-fora, rex.

appueaaon my 2s, 194s. serai No. 4159.041 4 claims. (ci. 16s-1s) Myinvention relates to new andv useful improvements in cement baskets foroil wells, and refers more particularly to a device attach'ed to thecasing for centering the casing during drilling Operations and servingas an obstruction during cementing to position the cemented olf zone.

On occasions it becomes necessary to introduce cement into the annularspace between the casing and the well bore above and below the producingformation. The cement when set serves to isolate different producingzones penetrated by the well bore, to prevent water from entering theproducing formations and to prevent side wall cavings from falling intothe formation and obstructing the ow of oil into the well. Cementbaskets attached to th'e casing below levels where the cement columnsare to be located form re- 'ceptacles and obstructions to downward flowof the cement.

The cement baskets are alxed to the casing at the surface and loweredwith the casing to the desired point in the well. They must be so shapedthat their flexible or expandible members will not be permanentlydistorted or bent by obstructions in the bore when the casing is eitherraised or lowered. They must be collapsible to conform to the unevencontour of the well bore and snugly fit the section of the bore whenpermanently located. Furthermore, it is desirable that the lowerportions of the baskets are closed to effectively support the cementcolumns.

An important object of my invention is to provide cement baskets for oilwells which are inherently flexible and to readily follow the contour ofthe well bore, and withstand the weight of the cement.

Another object of my invention is to provide cement baskets adapted toform closed receptacles when either expanded or contracted.

Still another object of my invention is to provide cement baskets thatare not permanently deformed by obstructions in the well bore eitherduring raising or lowering of the casing.

Other objects and advantages of my invention will be apparent during thecourse of th'e following description.

In the drawing forming a part of this specification and wherein likenumerals are employed to designate like parts throughout the same,

Fig. 1 is an elevational view showing a cement basket embodying lmyinvention mounted on av section of well casing.

the line 2--2 of Fig. 1,

Fig. 3 is a vertical sectional view taken on the line 3-3 of Fig. 1,parts being broken away for clearness of illustration,

Fig. 4 is a transverse sectional viewesimilar to that shown in Fig. 2with the basket contracted,

Fig. 5 is an enlarged transverse sectional view taken on the line 5-5 ofFig. 1,

Fig. 6 is an enlarged fragmentary `transverse sectional view taken onth'e line 8-6 of Fig. 1, and

Fig. 7 is an enlarged fragmentary transverse sectional view taken on theline 1-1 of Fig, 1.

Referring now to the drawing which shows a cement basket embodying myinvention attached to a section of well casing III. The basket is formedwith upper-and lower collars Il and I2 connected by a plurality ofout-bowed flexible strips I3. The ends of strips I3 are secured withinthe collars by riveting or welding. The inturned outside edges Ila andI2a of the collars snugly t the casing I0 spacing the collars sumcientlyfrom th'e casing to accommodate the attached ends of the exible stripsI3. As best shown inFigs. 1 and 3, the lower collar I2 is welded to thecasing, while the upper collar II has a limited axial movement thereon.Pins I4 fixed to and projecting radially from the casing I0 throughvertical elongated slots I5 in collar I I limit the movement of thecollar.

An inner second row of flexible strips I6 is positioned within th'eouter row of flexible strips I3. The lower ends of strips I6 areattached to the lower collar I2, while the free upper ends thereofterminate substantially midway the length of outer strips I3. As shownin Fig. 3 the inner free end strips I6 are spaced about thecircumference of the lower collar I2 so as t0 close the spaces orinterstices formed by spreading of the outer row of strips I3.

Both' the inner and outer rows of strips I3 and I6 are curved in crosssection substantially throughout the length of their contact as shown inFig. 6, but are fiat in cross section adiacent their attached lower endsas shown in Fig. 7. The ilat cross sectional portions of the stripsprovide resiliency for spreading oroutbowing of the strips and thecurved cross sectional portions provide reinforcement and stiffening ofthe strips above the resilient portions. Furthermore, the curved crosssectional shape of the strips causes the inner strips to conform withand lie at t against the outer strips when the latter are either yexpanded or contracted, the intimate contact between the strirs formingan essentially tight receptacle. l

When expanded the basket is normally atleast aslargeasthemaximumdiameterofthewell bore. When the casing and the basket are lowered intothe well the basket contracts when passing through constricted portionsof the well bore. i. e., collar Il slides upwardly on the casing and thebowed portions of strips i3 move toward the casing. The basket holds thecasing properly centered in the well bore so that cement injected intothe annular space will flow properly around the casing to form animpermeable plug. The cement flows intoI the basket which thus forms areceptacle and an obstruction for the cement.

It is to be understood that the form of the invention herewith shown anddescribed is to be taken as a preferred example of the same and thatvarious changes in the sizel shape and arrangement of parts may beresorted to without departing from the spirit of my invention or thescope of the appended claims.

Having thus described my invention, I claim:

1. In combination with a well casing, a cement basket and guidecomprising upper and lower collars surrounding and attached to the wellcasing, outbowed flexible strips fastened at their extremities to thecollars and extending lengthwise of the casing.' upstanding free endstrips anchored to the lower collar within the fastened outbowed stripsand extending only a portion of the distance between the collars, saidfree end strips overlapping adjacent outbowed strips to close the lowerportion of the spaces therebetween forming a receptacle surrounding thecasing.

2. In combination with a well casing, a cement basket and guidecomprising outbowed flexible strips extending lengthwise of the casing,said strips spaced around the circumference of the .well casing andfastened at their ends to the casing, upstanding free end strips withinthe fastened outbowed strips, said free end strips having their lowerends anchored to the casing and their upstanding portions overlappingadjacent outbowed strips to close the lower portion of the roundingthecasing.

3. In combination with a well easing a cemmt basket and guide comprisingoutbowed flexible strips extending lengthwise of the casing, said.spaces therebetween forming a receptacle, said fastened and free endstrips curved in cross section substantially throughout the length oftheir s contact and fiat in cross section adiacent their attached ends,the flat portions of said strips providing resiliency for spreading ofthe strips and the curved portions providing reini'orcment andstiii'ening for the receptacle portion of the basket.

4. In combination with a well casing a cement basket and guidecomprising upper and lower collars surrounding the well casing and atleast one of said collars aiiixed to the casing, outbowed flexiblestrips fastened at their extremities to the upper and lower collars,upstanding free ends flexible strips attached to the lower collar withinthe fastened outbowed strips and extending only a portion oi' thedistance between the collars. said free end strips overlapping adjacentoutbowed strips to close the lower portion of the spaces therebetween,forming a receptacle sur.

` rounding the casing. said fastened and free end for spreading of thestrips and the curved portions providing reinforcement and stiilfeningfor the receptacle portion of the basket.

JESBERHALL.

